The present invention relates to a convergence device for a color camera. It relates more particularly to a convergence device for a color camera in which the analysis of the image is achieved by combining a horizontal scanning movement and a vertical scanning movement adapted to each of the three fundamental colors.
Because of the separate processing for each of the three fundamental colors, it is generally difficult to obtain, on the fluorescent screen of the camera, perfect superimposition of the impact points of the electron beams corresponding to the three fundamental colors. This superimposition defect causes the presence of colored fringes on the contours of objects.
Traditionally, this defect of convergence of the electron beams is remedied by means of generators of signals, such as saw teeth, parabola, corner corrections etc. applied to the horizontal and vertical scanning means of the camera, and adjustable with potentiometers. These adjustments by means of potentiometers have the disadvantage of being long and tedious. Moreover, there always exists a residual error after adjustment.